Search carefully in places that look similar to the harder-to-find objects as more often than not that is where they will be hidden.
Hint Button
If you're struggling you can always click the 'hint' button to reveal the next piece of the puzzle which more often than not will be a bit you thought you didn't need.
Object Information
When you have tapped on an object to zoom in you can reveal more information about it by tapping again.
